INFICON XTC/C Thin Film Deposition Controller - Manual (Page 127)

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XTC/C - XTC/2 Operating Manual
4.13 Crystal Fail Inhibit
In many coating plants the crystal fail output relay closure is given major
importance and causes the entire system to shut down. This can cause
problems when the crystal is changed as part of the normal reloading
procedure. This potential conflict is resolved by utilizing the crystal fail inhibit
input; refer to
section 2.6.4 on page 2-23 . When this input is activated the
crystal fail relay will not close on crystal fail.
The crystal fail inhibit input is ignored if the instrument is in the Deposit state.
The front panel messages and instrument operation still work normally. The
operator may now change the crystal and verify that it is operating without
inducing a major process interruption.
The crystal fail inhibit input may be switched manually or automatically by using
the END DEPOSIT relay; refer to
section 2.6.5 on page 2-24 .
4.14 Shutter Delay
SHUTR DLY is used to establish rate control before exposing the substrates to
the evaporant. The sensing crystal must be exposed to the deposition source
during the Shutter Delay state for this to be accomplished. Shutter delay is
accessed by programming the SHUTR DLY parameter to Y (yes). The control
loop attempts to establish rate control at the end of the pre-deposition film
states. However, the source shutter opening is delayed for a period of time to
insure stable rate control. When rate control has been established (within 5%
or 0.5 Å of the DEP RATE value), the shutter opens, the accumulated thickness
is zeroed, and the substrates are immediately exposed to an evaporant that is
under tight rate control. With proper adjustment of the control loop parameters,
the delay time can be kept to a minimum. If the instrument is unable to establish
rate control in 60 seconds (or 20x CTL TC if the PID Loop is used and CTL TC
is greater than 3.0), the alarm relay on the AUX I/O will close. Also the
instrument may be set up to automatically STOP on this alarm condition if the
appropriate configuration switch is turned on; refer to
section 2.6.2 on page
2-19 .